ENERGY CENTS
By James Dulley
WaterFurnace
Geothermal pumps are efficient from the ground up Geothermal heat pumps are extremely energy efficient and generally yield the lowest utility bills of any residential heating and cooling systems available. With the high cost of energy today and the available energy tax credit, installing a geothermal heat pump could make economic sense for some families. A geothermal heat pump operates similarly to a standard heat pump except it exchanges heat with the ground instead of the outdoor air, essentially using renewable energy from the sun’s rays that This schematic show how a geothermal heat pump works during winter and summer. are stored as heat in the ground. The temperature of the outdoor air can vary 40 degrees or more from day to night and more than 100 degrees from the coldAnother summertime advantage is free hot water when est winter night to the hottest summer day. In contrast, the the geothermal heat pump is cooling your house. Instead of temperature several feet below the ground surface varies exhausting the waste heat to the outdoor air as a standard heat relatively little. pump does, this waste heat is diverted to your water heater. To capture the heat energy from the ground (in the This device is called a desuperheater and it is offered as a stanwinter) or exhaust the heat during summer, a long pipe is dard or optional feature on most geothermal heat pumps. usually buried in the ground. An antifreeze/water solution The initial cost of installing a geothermal heat pump is running through the pipe acts as the heat transfer medium. significantly more expensive than a standard air-to-air heat If there is a pond or wells that can be dug on your land, this pump, and the final cost of installation depends upon the water can run through the heat pump heat exchangers. All type of ground loop needed and your land’s topography. But of the new models use earth-friendly R410A refrigerant the federal energy tax credit, which provides a 30 percent tax instead of freon. credit covering the entire cost of installing a geothermal heat Since no outdoor condenser coils and fans are needed, pump, does make the initial expense more affordable. the entire heat pump and all mechanical components are To qualify for the credit, the efficiency of the unit must located in an indoor unit. It operates quietly and, with no meet or exceed Energy Star requirements and be installed outdoor fan or compressor, you and your neighbors won’t after Dec. 31, 2007 and before Dec. 31, 2016. hear any noise. For any units installed in The following companies offer During winter in the heating mode, a geothermal heat 2009 through 2016, you can efficient geothermal heat pump pump can produce up to $5 worth of heat for each $1 on take advantage of the full 30 systems: your electric bills. Unlike standard heat pumps that lose effi- percent tax credit. File for Climate Master (800) 299-9747 ciency and maximum heat output as the outdoor temperathe credit by completing the www.climatemaster.com ture drops, the efficiency and heat output from a geothermal Renewable Energy Credits Econar GeoSystems heat pump remains relatively constant. subsection on your tax (800) 432-6627 www.econar.com Moist ground has a huge thermal energy storage capacity. return forms. The contracFlorida Heat Pump (954) 776-5471 Some models can also be combined with solar systems to tor who sold and installed www.fhp-mfg.com gain more free heat. The most efficient models use a twothe product should list the Hydro-Temp (800) 382-3113 stage compressor and variable-speed indoor blower for the purchase as a “Geothermal www.hydro-temp.com best comfort. Heat Pump” on the invoice WaterFurnace (800) 436-7283 During summer months, a regular heat pump or central and that it “Exceeds requirewww.waterfurnace.com air conditioner loses efficiency and cooling output when it ments of Energy Star proHave a question for Jim? is hotter outdoors. Unfortunately, this is when your house gram currently in effect.” Send inquiries to: requires the greatest cooling capacity. Cooling efficiencies James Dulley, Carolina Country, James Dulley is an engineer for geothermal units are as high as 30 EER (energy efficiency and syndicated columnist for 6906 Royalgreen Dr., ratio). A standard heat pump or central air conditioner is Cincinnati, OH 45244 the National Rural Electric www.dulley.com typically less than half as efficient. Cooperative Association.
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32 JANUARY 2010 Carolina Country